Polyphase electromagnet strip guiding and tension device



Kim-12 SR Jafi. 17, 1956 R. s. BAKER 2,731,212

EOLYPHASE ELECTROMAGNBT STRIP GUIDING AND TENSION DEVICE Filed Feb. 13. 1953 3 Sheets-Sheet 1 FIG. .1. M P76. 2.

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United States Patent Oflice 2,731,212 Patented Jars. 17, use

POLYPHASE ELECIROMAGNET STRIP GUIDING AND TENSION DEVICE Richard S. Baker, Butler, Pa.

Application February 13, 1953, Serhl No. 336,744

9 Claims. (Cl. 242-75) This invention relates to strip coiling apparatus, and more particularly to an improved means for controlling the tension in metal strip as it is being coiled.

A main object of the invention is to provide a novel and improved electromagnetic strip guiding and tensioning device for controlling the tension in conductive strip material as it is being coiled, the improved device being simple in construction, involving relatively simple components, and providing accurately controllable tension on the metal strip being coiled, whether the strip is stationary or is moving.

A further object of the invention is to provide an improved electromagnetic strip tensioning and guiding device which can be employed on conductive strip material having a wide range of width, thicknesses and electrical resistivities, the improved tensioning and guiding device being useful for application to metallic strip of non-magnetic as well as nagnetic properties, and eliminating the necessity of ustng complicated and expensive arrangements of pinch rolls, current regulating devices on the coiler and uncoiler motors, clamps, or brake devices or a mechanical nature, the last-named improvement also eliminating the possibility of scratching or tearing the strip metal as it is coiled.

A still further object of the invention is to provide an improved electromagnetic strip tensioning and guiding device for use in coiling metal strip material; the improved device operating by generating eddy currents in the strip material and by producing motor action which may be utilized either to provide a restraining force on the metal strip in its motion toward the coiler, so that the strip may be tightly coiled by the coiler motor, which may be alternatively utilized in providing balanced guiding forces tending to maintain the strip in its required alignment, or in providing a combination of longtudinal restraining or aiding force on the strip and lateral correcting force to move the strip sideways as necessary to keep the strip edges in proper alignment.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a vertical longitudinal cross sectional view taken through a section of strip metal showing the arrangement or the polyphase electromagnetic tensioning devices above and below the strip.

Figure 2 is a vertical transverse cross sectional view taken through the strip of material of Figure 1, showing the electromagnetic tensioninng coils in front elevation.

Figure 3 is a schematic drawing illustrating the coiling and uncoiling rolls of strip and their associated driving motors, shown diagrammatically, and showing the arrangement of the strip tensioning magnets of Figures 1 and 2 relative to the strip and relative to a processing oven or other processing apparatus through which .the strip passes.

Figure 4 is a perspective view of one of the laminations employed in the magnet coils of Figures 1 and 2.

Figure 5 is a schematic wiring diagram illustrating the electricalconnections otthepolyphasecoilsamordingto polyphase elements being provided on the respective cores of the coils, instead or a single set of polyphase elements on each core as in Figures 1 and 2.

Figure 7 is a transverse vertical cross sectional view taken on the line 7-7 of Figure 6.

Figure 8 is a top plan view showing the arrangement of the strip tensioning coils of Figures 6 and 7 in alignment with the strips to provide a longitudinal force on the strips, such as a drag or pinch action.

Figure 9 is a top plan view showing a modified arrangement of polyphase magnetic coils arranged over opposite side marginal portions of the strip to provide lateral forces on the strip for correcting the longitudinal alignment of said strip, the magnets producing forces at right angles to the direction of movement of the strip.

Figure IOisatopplanviewsimilartoFigureQbut showing the coils arranged to provide combined longitudinal and lateral forces on the strip to provide a combination of dragging or pinching action together with lateral correcting force on the strip.

Reterringto the drawings, and more particularly to Figures 1 through 5 inclusive, 11 designates a section of strip material, such as conductive strip metal which is to be coiled on a roll 12 and which is uncoiled from a roll 13, as shown in Figure 3. The strip material 11 may be either non-magnetic metal, such as aluminum or copper strip, or may be material having magnetic properties, such as steel strip.

AashowninFigure 3, thestripiscoiledontherollfl by a coiler motor 14 which is suitably connected in any conventional manner to the coiling shaft of the'roll 12, and the strip is uncoiled from the roll'13 by an uncoiling motor 15, coupled similarly to the shaft arrying the coil 13. The strip 11 may be passed through a processing oven 16 or other processing apparatus as it is coiled on the roll 12 from the uncoiling roll 13.

Designated generally at 17 is a magnetic strip tension- I ing device in accordance with the present invention, said device being positioned between the uncoiling roll 13 and the processing device 16, as shown, or between the processing device 16 and the roll 12. The tensioning device 17 may comprise an upper polyphase magnet, designated generally at 18, and a lower polyphase magnet designated generally at 19, the upper magnet 18 being placed above and parallel to the top surface of the strip 11 and the lower magnet 19 being placed below and parallel to the bottom surface ofthe strip 11 in vertical alignment with the upper magnet 18, as shown in Figure l. The upper magnet 18 comprises a core 20 supported in any suitable manner in a direction extending longitudinally of the strip 11 and comprising a plurality of longitudinally extending laminations 21 formed with the registering notches 22, 23 and 24, as shown in Figure 4, respective coils 25,26 and 27 being positioned in said notches and surrounding the core 20, as shown in Figures land 2. The coils 25, 26 and 27 may be generally rectangular in shape and the core 20 may be engaged on the lower arms of the coils, as illustrated. The magnet 19 comprises a similar core 20' having identical laminations 21 and having the respective coils 25', 26'. and 27' engaged on the core and extending through the notches in the laminations, the core 20' being engaged with the top arms of the rectangular coils, as illustrated in Figure 2.

AsshownlnFigure l,thecoil25isinverticalalignmentwiththecoil25',andsaidcoilsextendatright angles to the direction or movement of the strip 11.

As above described, the magnets 38 and 38' may be arranged merely gbove the strip, or may have corresponding magnets below the strip to increase the magnitude of the correcting forces developed when the strip deviates from its centered position relative to the magnets.

Referring now to the form of the invention illustrated in Figure 10, the correcting magnets, shown at 48 and 48' are supported in any suitable manner in positions extending at equal acute'angles relative to the direction of travel of the strip 11. Each of the magnets 48 and 48' may be similar to the polyphase, multiple coil magnet 38, and the cores of the magnets 48 and 48 are similar to the cores 40 and 41. Said cores are oriented in the manner illustrated in Figure 10 so that they extend at equal and opposite acute angles relative to the direction of travel of the strip. Therefore, the traveling magnetic field produces equal and opposite motor actions having components which may be resolved along the 'direction of movement of the strip and also at right angles to the direction of movement of the strip. Therefore, the magnets 48 and 48' may be employed to provide a combination of either drag or retarding action plus laterally correcting action, or alternatively, a combination of aiding action on the strip plus laterally correcting action. As in the previously described forms of the invention, companion magnets may be employed below the strip in vertical alignment with the magnets 48 and 48' positioned above the strip. Alternatively, respective bundles of laminations may be provided below the strip in vertical alignment with respective magnets 48 and 48' to reduce the reluctance of the respective magnetic paths through the side marginal portions of the strip beneath the respective magnets 48 and 48'.

Any of the previously described devices may be employed in connection with conducting strip materials of a wide range of widths, thicknesses and electrical re sistivities. The devices perform best for given sizes of magnets when employed on materials having low resistance per unit of the volume exposed to the-magnets. The devices are usable on aluminum, copper or' brass strip, in thicknesses from foil to heavy plates. The polyphase magnetic devices of the present invention are superior to the present methods employed in strip tsnsiorv ing. in that the strip does nothave tocome into ac --1 tacwiththef ems ts. ceso 'not'arr iie tension oi a strip is controlled either by a complicated and expensive arrangement using pinch rolls the coiler and uncoiler and current regulating devices on motors, or by very c What is claimed is:

1. In an apparatus for coiling strip metal of the type having a pair of spaced parallel reels adapted to receive opposite coiled end portions of a strip of metal thereon and means for rotating said reels to move the strip from one reel to the other, a magnetic strip-tensioning device comprising a magnetic core mounted between said reels adjacent the plane of the strip, a plurality of spaced magnetizing windings surrounding said core and a polyphase energizing circuit therefor, said circuit being operable to energize said windings to produce a traveling magnetic field and thereby inducing a mechanical thrust in the strip in the direction of travel of said field.

2. An apparatus as defined in claim 1 in which the windings are positioned substantially parallel to the axes of the reels.

3. An apparatus as defined in claim 1 in which the windings are positioned at right angles to the axes of the reels.

4. An apparatus as defined in claim 1 in which the windings are positioned at a substantial angle to the axes of the reels.

5. An apparatus as defined in claim 1 in which there are provided vertically aligned magnetic cores above and below the plane of. the strip and having vertically aligned windings connected in the same phase with each other and operable upon energization to produce said traveling magnetic field extending between said magnetic cores and cutting across said metal strip.

6. An apparatus as defined in claim 5 in which the windings are positioned substantially parallel to the axes of the reels.

7. An apparatus as defined in claim 5 in whichthe windings are positioned at right angles to the axes of the reels.

8. An apparatus as defined in claim 5 in which the windings are positioned at a substantial angle to the axes of the reels.

9. Tension apparatus for use with strip metal moving means comprising a magnetic device for producing a motor thrust to tension said strip metal and comprising a magnetic core mounted adjacent the plane of and substantislly aligned with the strip, a plurality of spaced magnetizing windings surrounding said core and a polyphase energizing circuit therefor, said circuit being operable to energize said windings to produce a traveling magnetic held and thereby inducing a motor thrust in the strip in the direction of travel of said field.

ltshssnesscltedinthefileofthispatent UNITED auras PATENTS Re. 12,700 Zehden Oct. 1, 1907 282,165 Cheever July 31, 1883 1,140,460 Jseger May 25, 1915 1,386,813 Townsend Aug. 9, 1921 1,683,777 Hennessey Sept. 11. 1928 1,881,014 Ayers Oct. 4, 1932 1,906,211 Junker Apr. 25, 1933 2,393,243 Franz Jan. 22. 1946 2,433,014 Rendel Dec. 23, 1941 2,604,831 Fraeockel July 29, 1952 

